DEBRIS DISKS WITH HERSCHEL: AN OVERVIEW OF THE DUNES MODELING ACTIVITIES Jean-Charles Augereau, Steve Ertel, Alexander Krivov, Jérémy Lebreton, Torsten Löhne, Sebastian Müller, Philippe Thébault, Sebastian Wolf & the DUNES team: O. Absil, D. Ardila, M. Arévalo, A. Bayo, D. Barrado, C. Beichmann, G. Bryden, W. Danchi,C. del Burgo, C. Eiroa, D. Fedele, M. Fridlund, M. Fukagawa, B.M. González- Garcıa, E. Grün, R. Gutiérrez, A. M. Heras, I. Kamp, R. Launhardt, R. Liseau, R. Lorente, J. Maldonado, J. Marshall, R. Martínez-Arnaíz, G. Meeus, D. Montes, B. Montesinos, A. Mora, A. Morbidelli, H. Mutschke, T. Nakagawa, G. Olofsson, G. L. Pilbratt, I. Ribas, A. Roberge, J. Rodmann, J. Sanz-Forcada, E. Solano, K. Stapelfeldt, H. Walker, G. J. White
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Debris disks with Herschel : an overview of the DUNES modeling activities
Debris disks with Herschel : an overview of the DUNES modeling activities. Jean-Charles Augereau, Steve Ertel , Alexander Krivov , Jérémy Lebreton , Torsten Löhne , Sebastian Müller, Philippe Thébault, Sebastian Wolf - PowerPoint PPT Presentation
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DEBRIS DISKS WITH HERSCHEL:
AN OVERVIEW OF THE DUNES MODELING ACTIVITIES
Jean-Charles Augereau, Steve Ertel, Alexander Krivov, Jérémy Lebreton, Torsten Löhne, Sebastian Müller, Philippe Thébault,
Sebastian Wolf
& the DUNES team:
O. Absil, D. Ardila, M. Arévalo, A. Bayo, D. Barrado, C. Beichmann, G. Bryden, W. Danchi,C. del Burgo, C. Eiroa, D. Fedele, M. Fridlund, M. Fukagawa, B.M. González-Garcıa, E. Grün, R. Gutiérrez, A. M. Heras, I. Kamp, R. Launhardt, R. Liseau, R. Lorente, J. Maldonado, J. Marshall, R. Martínez-Arnaíz, G. Meeus, D. Montes, B. Montesinos, A. Mora, A. Morbidelli, H. Mutschke, T. Nakagawa, G. Olofsson, G. L. Pilbratt, I.
Ribas, A. Roberge, J. Rodmann, J. Sanz-Forcada, E. Solano, K. Stapelfeldt, H. Walker, G. J. White
Debris disks
KALAS et al. 2008
Another expression for planetary systems
Towards getting a complete picture of planetary systems
DUNES project Our own solar system is a debris disk (M. Wyatt’s talk).
Kuiper Belt (A. Krivov’s talk) Low luminosity extra-solar Kuiper Belt remained elusive
to previous space missions (A. Moro-Martin’s talk) Two Herschel Open Time Key projects :
Collisional: Radiative transfer, fed by results from collisional code ACE
that generates and evolves the disk “from the sources” ACE, SEDUCE and SUBITO codes (JENA)
Two modeling approaches, Three fitting strategies, Five codes
Advantages & limitations of the codes GRATER [Grenoble, J.-C. AUGEREAU & J. LEBRETON]
Fast exploration of large parameter spaces Stored grid for subsequent statistical analysis (24 million models for q1 Eri) Post-processing easy (e.g. re-computation of c2 with different weights) Simplistic description of the disk properties & no direct link to parent bodies
SAND [Kiel, S. ERTEL & S. WOLF] Fast: finds fit among ~1011 models in ~70 hours Large number of free parameters possible Limited initial constraints on disk physics Simplistic description of the disk properties & no direct link to parent bodies
ACE + SEDUCE + SUBITO [Jena, A. KRIVOV, T. LÖHNE, S. MÜLLER] Deep physical modeling of the disk from the sources Realistic description of disk properties Mass and dynamical excitation of unseen parent bodies CPU-demanding : 20 models in 3 months
GRAIN PROPERTIES: Close to 50-50 silicate-ice mixture Minimum grain size ~ 1.5 mm Size distribution: -3.5 power law
index
Best fit: DUST DISK & GRAIN
PROPERTIES: Mass : 0.02 Mearth
50-50 silicate-ice mixture
Coupled radial-size distribution
Collisional Approach (ACE+SUBITO+SEDUCE codes)
PARENT BELT: Location: 75-125 AU Eccentricities: 0.0…0.1 Mass : ~1000 Mearth (if 2 Gyr),
but ~ 100 Mearth (if 0.5Gyr)
Delayed stirring ?
See poster by S. Müller
Summary of model results
Consistent results between the three codes: Dust mass Grain size distribution Dust composition (ice likely) Parent belt position at ~ 75AU Dust surface density consistent
with a collisionally active debris disk
Open questions: Lacking inner (<5”) 70mm emission
Our unconvolved view of
the q1 Eri Kuiper Beltat PACS wavelengths
Deconvolved images
• Deconvolution with the MCS algorithm (Magain, Courbin & Sohy 1998, ApJ 494, 472)• Two blobs, suggestive of an inclined ring• Possible asymmetry between the two sides
70 µm
100 µm
The HD 207129 planetary system
pre-Herschel understandingA KUIPER-LIKE BELT
IRAS, ISO, Spitzer APEX/LABOCA: cold dust, with a fractional IR luminosity Ldisk/Lstar of ~1.4x10-4 (JOURDAIN ET AL. 1999, NILSSON ET AL. 2010, KRIST ET AL. 2010)
THE STAR Spectral type: G2 Distance : 15.6 pc Age : ~ 5 Gyr
PACS images
Disk resolved at all PACS wavelengths
Inclined, ring-like disk
Poster by LÖHNE ET AL.
Deconvolved PACS images
Brightness peak at around 130-140 AU
One of the most extended debris ring
Faint brightness asymmetry between the two ansae
Collisional Approach:
preliminary results Steady-state dust
production from a 85 Mearth planetesimal belt at 120 – 160 AU, and dust massof 6 x 10-3 Mearth
Lack of emission in the inner regions
Conclusions OBSERVATIONS
Images of extra-solar Kuiper belts with unprecedented resolutionand sensitivity
Inner gaps seen in thermal emission at <100mm for the first time
The belts show some degree of asymmetry MODELS:
Degeneracy between dust properties and disk structure broken thanks to the PACS images
Probing dust composition Probing collisional history: support to delayed stirring in the
case of q1 Eri (self-stirring by Plutos, or stirring by q1Eri c, or even by q1Eri b)
DUNES modeling “toolbox” works fine, we are ready for more data
More about q1 Eri: poster by MÜLLER More about HD 207129 : poster by